How you customize widgets in Celestial Reloaded will be up to you because this theme does not offer different styles for widgets, unlike the Encounters theme does (two very different themes). To create your own custom styles, you will need to know the basics of html and css to be able to do that. Then, to help assign those style classes to a widget, using a plugin like Widget CSS Classes will do what it does on the Encounters demo site.
Creating a link can be done from the WordPress post or page editor, but if you do your own custom links in content, you can also do your own HTML of it. Use this site for tutorials and reference: http://www.w3schools.com/html/html_links.asp
I used the same concept for my support page and added a css class to the link to give me the button style of a link. But my template here is quite different because it’s also Joomla and not WordPress :whistle: